Fuel injection system



ch 1, 1949. H. L. GATES FUEL INJECTION SYSTEM 2 Sheets-Sheet 1 FiledJuly 5, 1945 INVENTOR. Howard L 6afe$ D X ATTORNEY H. L. GATES I FUELINJECTION SYSTEM 2 Sheets-Sheet 2 Filed July 3, 1945 v/ ZIIIIIIIJI I iINVENTOR. Howard L. 68 fes Qui /LL ATTORNEY Patented Mar. 1, 1949 Pram"orrics (Granted under the act of March 3, 1883, as amended April 30,1928; 370 0. G. 757) Claims.

This invention relates to a fuel injection system forinternal-combustion engines.

An object of this invention is to provide a fuel injection system inwhich the injector, fuel supply and pumping mechanism all are mountedinternally of the engine cylinder.

Another object is to provide a fuel injection system in which thepower-transmitting piston and connecting rod of the engine form part ofthe fuel injector thereby eliminating auxiliary fuel injecting pumps andconnections.

Still another object is to provide a self-timing fuel injection systemin which the pressure on the piston created in the engine combustionchamber during the compression stroke provides the necessary pumpingforce for injection.

A further object is to provldea self-timing fuel injection system inwhich injection is controlled by the compression pressure in thecylinder combustion chamber, which, in turn, is controlled by adjustablemeans for varying the combustionchamber volume and hence the compressionratio.

Further objects and advantages of this invention, as well as itsconstruction, arrangement and operation will be apparent from thefollowing description and claims in connection with the accompanyingdrawings, in which,

Figure 1 is alongitudinal sectional view of a portion of a cylinder ofan internal-combustion engine showing the fuel injection systemcomprising this invention,

Figure 2 is a perspective view of a portion of the engineconnecting rodincluding the pumping housing of the fuel injector secured thereto, and

Figure 3 is a perspective view of a portion of the piston including thefuel-pumping plunger.

The fuel injection system comprising this invention includes a fuelinjecting pump and nozzle mounted in the piston of aninternal-combustion engine and a pumping chamber secured to theconnecting rod. The piston has limited axial motion with respect to theconnecting rod so that sufllcient pressure applied to the face of thepiston, as occurs during the compression stroke of the engine, resultsin fuel-pumping action and consequent injection of the fuel into thecylinder. The compression pressure in the combustion chamber of thecylinder governs the cycle time at which injection occurs and means areprovided to vary such time of injection by adjusting the volume of thecombustion chamber and hence the compression ratio.

In the drawings, there is shown in Figure 1 an internal-combustionengine of the two cycle type comprising a cylinder I having a bore 2,exhaust ports 3 and air inlet and scavenging ports 4. A finned cylinderhead 5 closes the top of the cylinder and a closure plug 6 is mounted inthe head 5 by screw threads for example. The plug 6 has a central cavityI which forms a continuation of the combustion chamber forming the upperportion of cylinder I. An adjustable shield or plunger 8 is slidablymounted in the cavity 1 for regulating the volume thereof. The plunger 8has a threaded shank 9 that engages the plug 6 as shown. The shank 9extends through the plug 6 and its end projects exteriorly of thecylinder head 5. A pinion 1 is secured to the end of the shank 9 andmeshes with an operating rack l0. Rotation of the pinion I by the rackin produces longitudinal adjustment of the plunger 8 within the cavity 1and thereby varies the volume of the latter as well as the volume of thecombustion chamber in the cylinder I.

A piston l I and connecting rod l2 are mounted in the bore 2 of thecylinder l. The connecting rod i2 is connected to the engine crankshaft(not shown) and the piston and connecting rod assembly reciprocates inthe cylinder bore 2. The fuel injector comprises a pumping housing I3having a pair of diametrically opposed trunnions M as shown in Figure 2which are suitably mounted in corresponding yoke arms 12a and nocomprising the forked end of connecting rod l2.'

A lateral extension member l5 forms part of pumping housing l3 and isspaced away from the trunnions l4 approximately 90 circumferentially.The pumping housing I3 is cylindrical in shape and has a central columnl6 forming an annular pumping chamber H. The column portion I6 of thehousing I3 is traversed by a fuel-oil duct [8 (see Figure. 1)terminating in an enlarged valve chambenIB. A branch l8a of duct I8leads to the pumping chamber I1, and the duct I8 at its opposite endconnects with an opening 20 in extension I5 (see Figure 2). A fuel-oilgland 59 (Figure 1) in the form of a hollow cylindrical body havingpartly closed ends is seated in the opening 20 of extension l5 and isprovided with an orifice aligned with the entrance to duct l8 as shownin Figure 1. A portion of the periphery of the pumping housing I3 isthreaded as shown at 2| Figures 1 and 2, and a regulating collar 22,which is internally threaded as at 23, is mounted thereupon. Theperiphery of the regulating collar 22 is provided with gear teeth' 24and an annular flange 25 on the regulating collar 22 overlaps the end ofthe pumping housing I3 as shown in Figures 1 and 2.

The piston II has a piston face I la and a skirt portion 21. A nozzlehousing 26 in the form of a hollow boss projects downwardly from theface lid of the piston i I into the interior thereof, the nozzle housing26 being coaxial with the piston as shown in Figures 1 and 3. The nozzlehousing 26 terminates in a flared annular stop shoulder 21 and has aninternally threaded bore 28 in whichthere is secure-d a fuel injectorpump member 29. Pump member 29 consists of plunger 36 in the 'form of a,hollow cylinder and a hollow threaded shank 3I that engages the threadedbore 28 in nozzle housing 26. The plunger portion 30 of fuel pump 29 isslidably mounted in the annular pumping chamber I! in pumpinghousing I3,and it fits the column I6 exteriorly and the bore of the chamber I'linternally, as shown in Figure 1. The piston I I is therefore fioatinglymounted with respect to connecting rod I2 and pumping housing I3 and hasrotatative and axial motion with respect to each of the latter. Theannular flange 25 on regulating collar 22 is interposed between theshoulder 21 on fuel plunger 26 and the top of pumping housing I3 tolimit the axial motion of the former with respect to the latter. Thiscomprises a translatory motion between the piston II and the connectingrod I2.

An injector nozzle 33 (Figure 1) is mounted in injector housing 26 andprojects slightly outwardly fromthe face Ila of piston 'II into thecombustion chamber formed between the cylinder head and piston face Nain cylinder I. A plurality of radially disposed fuel orifices 34 areprovided in the projecting portion of nozzle 33. The injector nozzle 33is secured in injector housing 26 by a hollow threaded nipple 35 whichis secured at one end by the internal threading 36 of the shank 3I offuel pump 29, the nozzle 33 being threaded to the nipple 35 at its otherend. One end of nipple'35 is partly closed by a conical valve seat 31which is connected by opening 38 to the hollow interior of the plunger29.

A spring-loaded fuel injection valve 39 is slidably mounted in theinterior of nipple 3I. The injection valve 39 consists of a cylindricalbody traversed by a series of longitudinally extending,

peripheral fuel-oil passages 40 and a conical closure member M whichseats in the valve seat 31. Valve spring 42, located within the nozzle33, normally holds valve 39 closed. A check valve 43 having grooves 44and a conical closure member 45 similar to valve 39 in structure isslidably mounted within the recess I9 of the core I6 of the pump bodyI3. The check valve 43 is normally held closed by check valve spring 46as shown in Figure 1.

An annular shoulder 41 extends circumferentlally around the innersurface of the skirt portion 21 of piston II as shown in Figures 1 and3.

' length adjacent where they are joined so that they are rotatablylocked together but capable of longitudinal sliding motion relative toeach other to causing combustion to take place.

permit tube 49 to reciprocate with the piston I I and crankshaft I2.Tube 49 is rotatably secured to the extension I5 on pump body I3 fortranslatory motion therewith, by means of a pair of thrust collars 5Iand 52 attached to tube 49. The portion of tube 49 which fits in gland59 is circular and rotatably mounted therein. A pinion 53 is fixedlymounted on the end of tube 49 and engages the peripheral gear 24 onregulating collar 22. The lower end of tube 50 is provided with a bevelgear 54 which is engaged by a control gear 55 driven by a manual orgoverner controlled shaft 56. Tube 56 is connected by a fitting 51 andsuitable flexible tube means 58 to a fuel supply pump (not shown).

A special gland is provided in chamber 29 of the crank l5 to permit fuelflowing in tube 49 to enter duct I3 in the plunger block I3 for allangular positions of adjustment of the tube 49. Such gland (Figure 1)comprises a bushing 59 having an annular chamber 62 and an outletOrifice 60 aligned with the entrance of duct I8 (Figure 2). A number ofradially disposed openings 6| are provided in the periphery of tube 49inside chamber 62 (Figure 1) so that there is continuous communicationbetween the interior of tube 49 and duct I8 as the former is rotatedrelative to the bushing 59.

The operation of the internal-combustion engine and the fuel injectionsystem is as follows:

Fuel oil is continuously supplied from a suitable low-pressure pumpingsource through the flexible connection 58 and 51 and thence throughtubes 59 and 49 into the chamber 62 of the gland 59. The fuel oil thenenters duct I3 where it fills the annular chamber I'I formed between theend of plunger 29 and pump housing I3. Inasmuch as fuel pump 29 isslidably mounted in the plunger body I3, the pressure of the fuel oil issufficient to raise fuel pump 29 and piston II with respect to the pumphousing I3 by an amount limited by the engagement of shoulder 41 onpiston II with extension I5 of the pumping housing I3, when the pressurein the combustion chamber is low, as, for example at the end of theexpansion stroke. At the same time, the fuel oil also flows past checkvalve 45 and fills chamber I9, but does not enter the inside of nozzle33 because in- .iection valve M is held closed by the relatively stronginjection pressure regulating spring 42.

During the compression stroke the pressure in the combustion chamberbetween the piston face I la and cylinder head 5 rises, until, at apredetermined point, the compression pressure acting over the pistonface Ila, forces the piston II together with plunger 30 of fuel pump 29downwardly axially with respect to the pumping chamber I1 therebypumping the fuel oil in chamber I9 through the injection valve M and outthrough the spray orifices 34-into the combustion chamber As the gasesexpand during the combustion or power stroke piston II is forceddownwardly, with shoulder 21 abutting shoulder 25 on regulating collar22 until the piston II uncovers-exhaustport 3and scavenging air port 4.When the piston has uncovered scavenging air port-4, the nozzle 33 isaligned therewith and the inrushing scavenging air cleanses whateverdeposits may have accumulated on the nozzle. At the completion of thecombustion stroke the pressure of the incoming fuel in fuel line 49 issufficient to again raise the piston II together with plunger 36 intococked position with shoulder 21 on injector housing 26 spaced fromregulatin collar 22 as previously-described and the cycle continues.

The amount of fuel injected per stroke is regulated for various load andspeed conditions by adjusting the gap between shoulder 21 and regulatingcollar 22. This is accomplished by adjusting operating shaft 56 which iscontrolled either by the engine governoror by a hand throttle, therebyrotating bevel gears 54 and 55, tubes 49, 50, pinion 53, and regulatingcollar 22. Collar 22 is thereby raised or lowered with respect to thepump body I 3 on which it is threadingly mounted to rotate in thethreaded engagement, thereby regulating the gap between the annularshoulder 25 on collar 22 and the flared shoulder 21 forming part ofpiston II. The amount of gap is directly proportional to the pumpingstroke of the injector mechanism and the amount of fuel injected isthereby proportionally controlled.

The pressure in the combustion chamber of the cylinder multiplied by theratio of the area of the piston face Ila to that of the pumping end ofplunger 29 determines the injection pressure of the fuel 011. Due to thefact that injection nor-' mally begins when the pressure of the air inthe combustion chamber is suflicient to overcome the resistance ofl'eredby injection valve 39, the cycle time at which fuel injection begins canbe regulated by increasing or decreasing the volume at the top of thecylinder, which regulates the cycle time at which the pressure due tocompression is of a magnitude suificient to initiate injection. Theadjustable plunger 8 is used to regulate in this way the point ofinjection. The operating rack I0, which may be coupled to the samegovernor actuated means as control shaft 56, or which may be manuallyadjusted, regulates the position of plunger 8 and hence the compressionratio in the engine cylinder, thereby to advance or retard the point ofinjection in response to various load conditions.

The injection pressure is also controlled by the strength of thedischarge-valve spring 42. Since the pressure acting on the fuel oilincreases as the piston I I moves upwardly on the compression stroke, aspring of suitable strength must be employed to prevent injection valve4I opening too early during the compression stroke.

Piston I I is free to rotate relative to the plun er body l3 andconnecting rod I2, since it is pivotallymounted with respect to thelatter by the engagement of plunger 29 with plunger body I3. Such freelyfloating piston arrangement is advantageous inasmuch as it distributeswear between the piston II and cylinder wall 2. The piston II i normallyheld from comin off the connecting rod I2 by the annular shoulder 41secured to the skirt of piston I I as shown in.Figures 1 and 3 abuttingextension I5. The limit lugs 48 at each end of shoulder 41 prevent thepiston II rotating to a point where the gap between the ends of shoulder4'! would align with arm I5. When it is desired to remove piston II forservicing after cylinder head 5 ha been removed, regulating collar 22 isscrewed all the way down until flange 25 abuts plunger housing I3. Thisleaves a wide gap between flange 25 and the flange 21 on the injectorhousing 26. Piston II can now be rotated until arm I5 clears the limitlugs 48 and is aligned with the gap between the ends of shoulder 4'!previously mentioned, after which piston II can be removed. The externalperiphery of nozzle 33 has suitable flats or wrench slots to permit easyremoval thereof. Each cylinder moreover can be easily isolated byreinoval of plug 6 in the cylinder head 5, thereby venting the cylinderto the atmosphere.

Various modifications and changes may be made in the above describeddevice without departing from the spirit and scope of this invention asset forth in the appended claims.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

What is claimed is:

1. In an internabcombustion engine having a reciprocating piston andconnecting rod, the combination of -a fuel injector comprising a spraynozzle mounted in said piston, a floatable mounting between said pistonand connecting rod, said floatable mounting including a pumping chambersecured to the connecting rod and a fuel injection pump secured to saidpiston and movably mounted in said pumping chamber, said piston beinmovable relative to said connecting rod in response to pressure exertedon said piston during the compression stroke of said engine.

2. In an internal-combustion engine having a combustion cylinder and apower transmitting reciprocating connecting rod, the combination of apumping chamber secured to said connecting rod, a piston slidablymounted in said cylinder, a fuel injecting plunger secured to saidpiston and slidably mounted in said pumping chamber to form a floatableconnection between said connecting rod and piston, and a fuel spraynozzle mounted in said piston and having access to the combustionchamber of said engine, said piston and said fuel injecting plungerbeing movable relative to said pumping chamber in response to pressureexerted on said piston during the compression stroke of said engine.

3. A fuel injection system for internal-combustion engines having acylinder and power transmitting connecting rod reciprocating thereincomprising, a fuel pumping chamber secured to said connecting rod, apiston slidably mounted in said cylinder, a fuel injecting plungersecured to said piston and slidably mounted in said pumping chamber toform a floatable connection between said connecting rod and piston, afuel spray nozzle mounted in said piston exposed to the combustionchamber of said cylinder, a fuel passage connecting said fuel pumpingchamber with said fuel spray nozzle, said piston and said fuel injectingplunger being movable with respect to said pumping chamber in responseto pressure exerted on said piston during the compression stroke of saidengine.

4. A fuel injection system for internal-combustion engines' having acylinder and power transmitting connecting rod reciprocating thereincomprising, a fuel pumping chamber secured to said connective rod, apiston slidably mounted in said cylinder, a fuel injecting plungersecured to said piston and slidably mounted in said pumping chamber foraxial and rotative movement relative thereto, a fuel spray nozzlemounted in said piston and exposed to the combustion chamber of saidcylinder; fuel passage means connecting said pumping chamber with saidspray nozzle, valve means in said fuel passage regulating the flow offuel to said nozzle, and elastic means engaging said'valve means tonormally hold the latter closed; said piston and said fuel injectingplunger being movable relative to said pumping chamber in response topressure exerted on said piston during the compression stroke of saidengine, whereby fuel in said pumping chamber is forced through said fuelpassage and valve into the combustion chamber of said engine.

5. A fuel injection system for internal-combustion engines having acylinder and power transmitting connecting rod reciprocating thereincomprising, a fuel pumping chamber secured to said connecting rod, apiston. slidably mounted in said cylinder, a fuel injecting plungersecured to said piston and slidably mounted in said pumping chamber foraxial and rotative movement relative thereto, a fuel spray nozzlemounted in said piston and exposed to said combustion chamber of saidcylinder, a fuel passage connecting said fuel pumping chamber with saidspray nozzle, said piston and said fuel injecting plunger being movablewith respect to said pumping chamber in response to pressure exerted onsaid housing to permit free flow of fuel therebetwen as the fuel line isrotated relative to said pumping housing.

9. A fuel injection system for internal-combustion engines comprising, afuel pumping housing secured to a connecting rod of said engine, anannular fuel pumping chamber in said pumping housing, a hollow pistonhaving a face portion piston during the compression stroke of saidenglue, and regulating means adjustably mounted ,on said pumpingchamber, said regulating means said cylinder, a fuel injecting plungersecured to regulating collar axially of said pumping chamber whereby theshoulder on said regulating collar inand skirt portion, an annular fuelplunger pro jecting from the face portion of said piston, said fuelplunger being slidably receivable in said annular fuel pumping chamberfor reciprocating and rotative motion therein, shoulder means on saidfuel plunger, a fuel spray nozzle mounted in the face portion of saidpiston coaxially with said fuel plunger, a fuel passage connecting. saidannular fuel pumping chamber with said spray nozzle, a regulating collaradjustably mounted on 'said fuel pumping housing for axial movementrelative thereto, a shoulder on said regulating collar interposedbetween said fuel pumping housing and said shoulder means on said fuelplunger, said piston being axially movable relative to said pumpinghousing upon application of pressure on the face portion of said piston,and means for adjusting the position of said terposed between said fuelplunger shoulder and said pumping housing limits the amount of axialmovement between said piston and said pumping said piston'and slidablymounted in said pumping chamber, a fuel spray nozzle mounted in saidpiston and exposed to said combustion chamber of said cylinder, a fuelpassage connecting said fuel pumping chamber with said spray nozzle,said piston and said fuel 'injectingplunger being movable with respectto said pumping chamber in response to pressure exerted on said pistonduring 7 the compression stroke of said engine, regulating meansadjustably mounted on said pumping chamber, stop means on saidregulating means interposed between said plunger and said pumptatablymounted with respect to each other and connectable at one end to a fuelsupply source.

8. A fuel injection system for internal-combustion engines comprising afuel pumping housing secured to a connecting rod of said engine, anannular fuel pumping chamber in said pumping housing, a hollow pistonhaving a face portion and skirt portion, an annular fuel plungerprojecting from the face portion of said piston, said fuel plunger beingslidably receivable in said annular fuel pumping chamber for axial androtative motion therein, a fuel spray nozzle mounted in the face portionof said piston coaxially with said fuel plunger, a fuel passageconnecting said annular fuel pumping chamber with said spray nozzle, afuel check valve and a spring loaded fuel injection valve mounted insaid passage, a fuel supply line rotatably mounted in said pumpinghousing, said fuel line being secured to said pumping housing fortranslatory motion therewith, and gland means connecting said fuelsupply line with said fuel passage in said pumping housing.

10. In an internal-combustion engine having a cylinder, cylinder headand reciprocating connecting rod, the combination of a cavity in said.cylinder head accessible to said cylinder, a shield adjustably mountedin said cavity for varying the volume thereof, operating means connectedto said shield, a fuel pumping chamber mounted on said connecting rod, apiston having a face por: tion and skirt portion slidably mounted insaid engine cylinder, a fuel pumping plunger secured to said piston andslidably mounted in said fuel pumping chamber, a fuel spray nozzlemounted in said face portion of said piston accessible to the combustionchamber of said engine cylinder, a fuel passage connecting said fuelpumping chamber to said nozzle, said piston and said fuel pumpingplunger being movable relative to said pumping chamber in response topressure applied on the face portion of said piston, adjustable stopmeans between said fuel pumping plunger and said fuel pumping chamberfor limiting the amount of motion therebetween, and control means foroperating said adjustable stop means, said control means and said firstmentioned shield operating means being responsive to load variations onsaid engine.

11. In an internal-combustion engine having a cylinder, cylinder headand power transmitting connecting rod reciprocally mounted in saidcylinder, the combination of a fuel injector comprising a powertransmitting piston slidably mounted in said cylinder, fuel pumpingmeans secured to said piston, a fuel pumping chamber secured to saidconnecting rod, said fuel pumping chamber slidably receiving said fuelpumping means on said piston and forming a fioatable connection betweensaid connecting rod and piston, a fuel spray nozzle in said piston and afuel passage connecting said fuel pumping chamber to said nozzle, saidpiston being axially movable relative to said fuel pumping chamber inresponse to pressure applied to said piston.

12. In an internahcombustion engine having a cylinder, cylinder head andpower transmitting connecting rod reciprocally mounted in said cylinder,the combination of a fuel injector comprising a power transmittingpiston slidably mounted in said cylinder, fuel pumping means secured tosaid cylinder, a fuel pumping chamber secured to said connecting rod,said fuel pumping chamber slidably receiving said fuel pumping means onsaid piston for combined axial and rotatable motion relative thereto, afuel spray nozzle in said piston, a fuel passage connecting said fuelpumping chamber with said fuel spray nozzle, spring loaded injectionvalve means in said fuel passage, said fuel pumping means being axiallymovable relative to saidpumping chamber in response to pressure appliedto said piston, a cavity in said cylinder head and adjustable means forvarying the volume of said cavity and hence the compression ratio insaid cylinder, whereby the cyclic time at which the pressure on saidpiston required to open said injection valve can be varied in responseto said volumetric variation.

13. In an internal-combustion engine the combination of a combustioncylinder, a power transmitting piston and connecting rod mounted forreciprocating motion therein, said piston being floatably mounted uponsaid connecting rod, said floatable mounting including a fuel pumpingchamber secured to one of said connecting rod and piston elements and afuel injecting plunger secured to the other of said elements andslidably mounted within said fuel pumping chamber.

14. In an internal-combustion engine the combination of a combustioncylinder, a power transmitting piston and connecting rod mounted forreciprocating motion therein, said piston being 10 floatably mountedupon said connecting rod, said fioatable mounting including a fuelpumping chamber secured to one of said connecting rod and pistonelements and a fuel injecting plunger secured to the other of saidelements and slidably mounted within said fuel pumping chamber,

secured one to the connecting rod and the other to the piston, themounting of the connecting rod for the piston comprising a translatorymotion to provide relative movement between the plunger and the pumpingchamber to operate the injector pump.

HOWARD L. GATES.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,102,019 Dorwald June 30, 19141,162,789 Loane, Jr. Dec. '7, 1915 1,349,515 Lombard Aug. 10, 19201,622,266 Ake Mar. 29, 192'! 2,067,997 White Jan. 19, 1937 2,132,083Pescara Oct. 4, 1938 2,203,669 Butler June 11, 1940 Whitfield Feb. 18,1941 Certificate of Correction Patent N 0. 2,462,854. March 1, 1949.

HOWARD L. GATES 4 It is hereby certified that errors appear in theprinted specification of the above numbered patent requiring correctionas follows:

, Column 2, line 38, before the word housing insert pumping column 3,line 20, 5" for floatingly read floatabl'y; lines 27, 28 and 29, strikeout This comprises a translatory motion between the piston 11 and theconnecting rod 12. and insert the same in line 19, same column, beforeThe pistons; column 5, line 12, strike out threadingly and that the saidLetters Patent should be read with these corrections therein that thesame may conform to the record of the case in the Patent Oflice.

Signed and sealed this 26th day of July, A. D. 1949.

THOMAS F. MURPHY,

Assistant Oomn iuioner of Patents.

